The shares dropped 45 Canadian cents, or 2.3 percent, to C$19.05 in the first trading day since Randy Eresman, 54, said late on Friday that he planned to leave his position immediately and retire.

Board member Clayton Woitas, an experienced Canadian oil and gas executive, is assuming Eresman’s position while Encana searches for a permanent replacement.

Analysts said the appointment of an interim CEO might be a signal that the company is up for sale. Nexen Inc NXY.TO sold itself to China’s state-owned CNOOC Ltd (0883.HK) after its chief executive officer was fired last year and an interim CEO was put in place.

New federal rules limiting foreign investment by state-owned companies may reduce the number of potential buyers for Encana, which has a market capitalization of C$14.3 billion ($14.5 billion). But its massive natural-gas reserves from conventional and shale-gas fields in Canada and the United States could attract the attention of deep-pocketed international oil companies looking to supply liquefied natural gas projects.

“The appeal of Encana as an (acquisition) target relates primarily to their vast feedstock of gas opportunities to support LNG development both on West Coast Canada and on the U.S. Gulf Coast,” CIBC World Markets analyst Andrew Potter said in a research note.

“Although Eresman’s retirement increases the possibility of Encana being acquired,” Potter said, “we note that we still only regard this as a 30 to 40 percent chance due to the large size and limited number of buyers.”

However others said Encana should acquire an oil producer in order to accelerate a push to diversify out of natural gas production, even though such a purchase might add further debt to an already debt-heavy balance sheet.

“They are going to have to start down that path, as painful as it may be,” said John Stephenson, a portfolio manager at First Asset Capital Corp, which owns Encana shares.

Encana was not immediately available for comment.

Eresman gave no reason for his departure. He said in a release that he believes the company is financially and operationally sound and that its effort to move away from its focus on natural gas and produce more oil was on track.

However he faced criticism from investors for overspending on natural gas production when prices were falling and for spinning off the company’s lucrative oil sands operations into Cenovus Energy Inc (CVE.TO) despite weakening natural gas prices.

Eresman’s resignation also comes as the U.S. Department of Justice probes whether the company illegally colluded with Chesapeake Energy Corp (CHK.N) to lower the price of Michigan exploration lands.

Encana said last year that an internal investigation had determined it did not collude with the U.S. gas producer. However, it offered no details on its investigation and did not say how it reached that conclusion.

Reporting by Scott Haggett; Editing by Lisa Von Ahn and David Gregorio